A Long Term Evolution (LTE) system, a Long Term Evolution Advanced (LTE-A) system and an International Mobile Telecommunication Advanced (IMT-Advanced) system are all based on an Orthogonal Frequency Division Multiplexing (OFDM) technique.
In an OFDM system, data mainly exists in the form of time-frequency; in the LTE and LTE-A, a Resource Block (RB), which is called a Physical Resource Block (PRB) when mapped to physical resource, is defined as continuous OFDM symbols in a slot in time domain, and 12 or 24 continuous subcarriers in frequency domain, thus, 1 RB consists of Nsymb×NscRB Resource Elements (REs), where Nsymb represents the number of OFDM symbols in a slot; and NscRB represents the number of continuous subcarriers of the RB in the frequency domain.
Meanwhile, the system also defines the concept of RB group, namely, several continuous RBs are called an RB group; the size of the RB group is determined by a system bandwidth, for example, when the system bandwidth is of less than or equal to 10 RBs, the size of the RB group is 1 RB; when the system bandwidth is of 11 to 26 RBs, the size of the RB group is 2 RBs; when the system bandwidth is of 27 to 63 RBs, the size of the RB group is 3 RBs; and when the system bandwidth is of 64 to 110 RBs, the size of the RB group is 4 RBs.
After a relay technique is introduced to the LTE-A system, as shown in FIG. 1, the link between an eNode-B and a Relay Node (RN) is called a backhaul link or a relay link; the link between the RN and User Equipment (UE) is called an access link; and the link between the eNode-B and the UE is called a direct link.
In the LTE-A system, the R-PDCCH introduced is mainly to solve the problem that the RN cannot receive the Physical Downlink Control Channel (PDCCH) of the eNode-B. At present, the research on multiplexing mode between a control channel and a service channel, after the RN is introduced, is a hot topic, for example, adopting Frequency Division Multiplex (FDM), or FDM+Time Division Multiple (TDM) to perform multiplexing; however, no solution has been provided for the resource allocation of the R-PDCCH.
In the disclosure, the FDM mode refers to that the R-PDCCH and a Relay link-Physical Downlink Shared Channel (R-PDSCH) are transmitted in different PRBs; FDM+TDM mode refers to that the R-PDCCH and the R-PDSCH are transmitted in the same or different PRBs.
When the relay node performs demodulation in the condition of a Demodulation Reference Signal (DMRS), if some relay node has Relay link-Downlink grant (R-DL grant) only, the network side maps the R-DL grant to the first slot, maps or does not map data to the second slot; if some relay node has both R-DL grant and Relay link-Uplink grant (R-UL grant), the network side maps the R-DL grant to the first slot and maps the R-UL grant to the second slot; and if some relay node has R-UL grant only, the network side maps the R-UL grant to the second slot and does not map data to the first slot.
When the relay node performs demodulation in the condition of a Cell-specific Reference Signal (CRS), the network side maps the R-DL grant to the first slot and maps the R-UL grant to the second slot.
Frequency diversity scheduling refers to a scheduling mode or transmission mode capable of acquiring diversity gain in the frequency direction, for example, interleaving control channels of multiple relay nodes together by the network side can be viewed as frequency diversity scheduling.
Frequency selective scheduling refers to a scheduling mode or transmission mode which performs scheduling according to channel quality, for example, scheduling a resource location corresponding to the control channel of some relay node according to channel quality by the network side can be viewed as frequency selective scheduling.
In the disclosure, the RB occupies several subcarriers (for example, 12 subcarriers) in the frequency direction and all OFDM symbols of a slot in the time direction; an RB pair refers to a pair of RBs corresponding to two slots in a subframe; the frequency resource occupies several subcarriers (for example, 12 subcarriers) in the frequency direction, and several OFDM symbols or all OFDM symbols of a slot or subframe in the time direction; and the frequency resource is equivalent to the RB or the RB pair in terms of concept when occupying all the OFDM symbols of a slot or subframe in the time direction. FIG. 2 shows a structural diagram of an existing frame, where snowflake point shade represents a wireless frame; oblique line shade represents a subframe; and blank squares represent OFDM symbols. FIG. 3 shows a diagram of an RB and subcarriers.